In a previous message I did not know for sure what the abbreviation was for the parsec. I have found the correct abbreviation to be pc (not ps).
1 pc = 30.857 Pm Regards, Bill Hooper physics professor (retired), Florida, USA P.S. For those unfamiliar with the parsec, it is defined as the distance to a star if that star exhibits a solar paralax of 1 second of arc. Solar paralax is defined as the angular difference between the apparent position of a star (measured against more distance background stars) as seen from the Sun and the apparent position of the star as seen from Earth at a position in it's orbit 90 degrees from the direction to the star. (In practice, the position of the star can be measured from the Earth at opposite points in its orbit, each 90 degrees from the star, with the resulting angular difference being divided by 2.) ======================== Keep It Simple - Make It Metric! ========================
